Enhancement of Stability and Conductivity of α-Fe₂O₃ Anodes by Doping with Cs⁺ for Lithium-Ion Battery

Reconstructing nanostructures by doping metal oxides can improve the performance of lithium-ion batteries (LIBs). Herein, Cs-doped α-Fe 2 O 3 (α-Fe 2 O 3 /Cs) nanoparticles were synthesized via chemical coprecipitation and thermal treatment methods. Cs doping resulted in reduced particle size, increased lattice spacing, and enhanced conductivity of the composite materials. Density functional theory (DFT) calculations demonstrated that the band gap was reduced to 0.21 eV. The testing of the as-obtained α-Fe 2 O 3 /Cs as anode materials of LIBs resulted in an initial discharge/specific capacity of 2918 mAh g –1 and a reversible discharge capacity of 973 mAh g –1 at 200 mA g –1 after 300 cycles. At a high current density of 4000 mA g –1, the reversible discharge capacity of the α-Fe 2 O 3 /Cs anode was still as high as 472 mAh g –1, which was higher than that of Fe 2 O 3 (245 mAh g –1 ). A significant contribution of the capacitively controlled behavior to the lithium-ion storage in α-Fe 2 O 3 /Cs was demonstrated by cyclic voltammetry (CV) analysis. Overall, the proposed strategy looks promising for developing advanced nanoparticle Fe 2 O 3 -based anode materials for high-practicability LIBs to meet good social and economic benefits of sustainable development.